Issue with Seiko 4006 Movement: Alarm Bolt Yoke Problem

[TimepieceTinkerer]

Hello watch enthusiasts,

I'm encountering a peculiar issue with my Seiko 4006 movement and could use some advice. Specifically, the alarm bolt yoke doesn't function properly when I tighten the screw on the calendar plate directly above it. This results in the alarm not functioning as it should. However, when I leave the screw loose, everything works perfectly and alarm bolt yoke is functional as should be.

I've tried replacing the alarm bolt yoke, the alarm bolt yoke spring, and even the calendar plate itself, but unfortunately, none of these changes have made a difference. The only workaround I've found is to keep the screw on top of the alarm bolt yoke loose.

Has anyone else experienced a similar issue or have any insights on what might be causing this? I'll also be sharing pictures to help illustrate the problem.

Looking forward to your suggestions and advice!

TT

[RichardHarris123]

Is it the correct screw? 

[AndyGSi]

What does the boss look like where the screw is and the alarm bolt yoke fits over.

Is everything flat including the setting lever and yoke spring.

Also something doesn't look right with that yoke spring.

[Curare]

I have attached some photos of my recent 4006 service taken during disassembly.

May be of assistance?